Be used for the transformation manifold type plasma window of etch chamber and comprise its etch chamber
Technical field
The present invention relates to semiconductor fabrication process, particularly be used for the transformation manifold type plasma window of etch chamber and comprise its etch chamber.
Background technology
Etching is a unusual critical step in the semiconductor technology.Dry etching in the semiconductor technology all is in the etch chamber of airtight vacuum, to carry out.Fig. 1 shows the schematic cross-section of existing etch chamber, and Fig. 2 shows the existing schematic top plan view that is used for the transformation manifold type plasma window of etch chamber.Like Fig. 1, shown in Figure 2; The top of etch chamber 100 is provided with transformation manifold type plasma window 101 (Transformer Coupled Plasma; TCP), transformation manifold type plasma window 101 is provided with air admission hole 102, is set with Electrostatic Absorption dish 103 (Electric Static Chuck between two parties in the bottom of etch chamber 100; ESC), the outer setting in etch chamber 100 has top anode 104 and bottom cathode 105.When silicon wafer or polysilicon are carried out dry etching; At first silicon wafer or polysilicon are placed on the Electrostatic Absorption dish 103; In etch chamber 100, feed etching gas through air admission hole 102 then; Etching gas inner surface at the TCP window under the effect of the RF energy that top anode 104 produces produces plasma, and these plasmas are shifted to silicon wafer or polysilicon under the suction-operated of bottom cathode 105, thereby silicon wafer or polysilicon are carried out etching.
Because the material of TCP window 101 is quartzy; Its main component is a silicon dioxide, and therefore, the etching gas of etch silicon wafer or polysilicon will loss TCP window 101; Generally can make the thickness of TCP window 101 reduce hundreds of microns; This not only causes the shortening in the useful life of TCP window 101, but also can make the plasma of generation and need the silicon wafer of etching or the distance between the polysilicon to become big, influences the effect of etching; And the forms chip that comes off drops on the surface of silicon wafer or polysilicon, forms the barrier layer, influence etched proceeding, and forms faulty goods, thereby the yield that influences product also will reduce the stability of etching technics.
The method that solves the defective workmanship of bringing because of the varied in thickness of TCP window in the prior art is: silicon wafer or polysilicon after the observation etching; Because after the thickness of TCP window reduces; Accelerate or slack-off to the etching speed of silicon wafer or polysilicon is corresponding; Therefore observe and the silicon wafer of the etching of record or the etching effect of polysilicon, adjust the time of main etch step in the etching technics next time, thereby make etching technics reach the etching effect of expection.But this method needs the engineer very accurate to the assurance of etching effect, and needs the record and the test of repeated multiple times, just can reach etching effect preferably.
Therefore need provide a kind of technology stability better TCP window,, guarantee that simultaneously the distance between etching process ionic medium body and the sample is constant, thereby reduce the defective of semiconductor device structure to avoid etching gas in the etching technics to the loss of TCP window.
Summary of the invention
In the summary of the invention part, introduced the notion of a series of reduced forms, this will further explain in the embodiment part.Summary of the invention part of the present invention does not also mean that key feature and the essential features that will attempt to limit technical scheme required for protection, does not more mean that the protection range of attempting to confirm technical scheme required for protection.
A kind of transformation manifold type plasma window that is used for etch chamber comprises transformation manifold type plasma window matrix, it is characterized in that: the inner surface of said transformation manifold type plasma window matrix is formed with protective layer.
The material of said protective layer is yttria or zirconium dioxide.
The material of said protective layer is the mixture of yttria and alundum (Al or the mixture of zirconium dioxide and alundum (Al.
The percentage that the weight of said alundum (Al accounts for said mixture total weight amount is smaller or equal to 10%.
The percentage that the weight of said alundum (Al accounts for said mixture total weight amount is 7% ~ 8%.
The thickness of said protective layer is 10 ~ 20 microns.
Said protective layer adopts the method for plasma spraying to form, and wherein, the temperature of plasma jet is 12000 ~ 20000 ℃.
A kind of etch chamber is characterized in that, the top of said etch chamber comprises transformation manifold type plasma window matrix, and the inner surface of said transformation manifold type plasma window matrix is formed with protective layer.
The material of said protective layer is yttria or zirconium dioxide.
The material of said protective layer is the mixture of yttria and alundum (Al or the mixture of zirconium dioxide and alundum (Al.
The percentage that the weight of said alundum (Al accounts for said mixture total weight amount is smaller or equal to 10%.
The percentage that the weight of said alundum (Al accounts for said mixture total weight amount is 7% ~ 8%.
The thickness of said protective layer is 10 ~ 20 microns.
Said protective layer adopts the method for plasma spraying to form, and wherein, the temperature of plasma jet is 12000 ~ 20000 ℃.
The inner surface of TCP window of the present invention is coated with layer protective layer; The TCP window of this structure can be avoided the loss of etching gas to its generation; The useful life of the TCP window that has prolonged; The thickness that guarantees the TCP window simultaneously can not reduce, and the distance between plasma and the sample can not changed, and then etching technics can be produced a desired effect.In addition, because protective layer has produced good protection to the TCP window, do not drop on the surface of silicon wafer or polysilicon so do not have the forms chip that comes off yet, thereby improved the stability of etching technics.TCP window construction of the present invention is simple, is convenient to make, and can be widely used in the TCP window of the etch chamber in the semiconductor manufacturing equipment.
Description of drawings
Attached drawings of the present invention is used to understand the present invention at this as a part of the present invention.Embodiments of the invention and description thereof have been shown in the accompanying drawing, have been used for explaining principle of the present invention.In the accompanying drawings,
Fig. 1 is the schematic cross-section of existing etch chamber;
Fig. 2 is the existing schematic top plan view that is used for the transformation manifold type plasma window of etch chamber;
Fig. 3 is the schematic cross-section of structure of the TCP window that is used for etch chamber of the embodiment of the invention;
Fig. 4 is the schematic cross-section of the etch chamber of TCP window inner surface belt matcoveredn according to another embodiment of the present invention;
Fig. 5 forms the schematic cross-section of the spraying equipment of protective layer according to the embodiment of the invention at TCP window inner surface.
Embodiment
In the description hereinafter, a large amount of concrete details have been provided so that more thorough understanding of the invention is provided.Yet, it will be apparent to one skilled in the art that the present invention can need not one or more these details and be able to enforcement.In other example,, describe for technical characterictics more well known in the art for fear of obscuring with the present invention.
In order thoroughly to understand the present invention, specific embodiments of the invention is described in detail hereinafter, so that how explanation the present invention solves the problem that the TCP window is depleted in etching process.Obviously, execution of the present invention is not limited to the specific details that the technical staff had the knack of of semiconductor applications.Preferred embodiment of the present invention is described in detail as follows, yet except these were described in detail, the present invention can also have other execution modes.
Fig. 3 shows the schematic cross-section according to the structure of the TCP window that is used for etch chamber of the embodiment of the invention.As shown in Figure 3, TCP window 300 comprises the protective layer 302 of TCP window matrix 301 and inner surface thereof.Protective layer 302 is used to protect TCP window matrix 301, to avoid the loss of etching gas to its generation.Thereby influence the etching technics effect for fear of the attenuation of TCP window, avoid simultaneously etching gas that the TCP window is produced loss preferably, can not make the forms chip that comes off drop on the surface of silicon wafer or polysilicon again, the thickness of protective layer can not be too thick can not be too thin.Preferably, the thickness of said protective layer 302 is 10 ~ 20 microns.
The material of said protective layer 302 is the material of anti-plasma corrosion, and preferred, the material of protective layer 302 is yttria (Y
2O
3) or zirconium dioxide (Z
rO
2).Because Y
2O
3And Z
rO
2All have high temperature resistant, corrosion resistant characteristics, and have very high intensity and toughness, therefore when they are used to make protective layer 302, can make the corrosion resistance of TCP window 300 higher.
In addition,, avoid protective layer 302 to come off from TCP window matrix 301 in order to increase the adhesiveness between protective layer 302 and the TCP window matrix 301, can be to Y
2O
3Perhaps Z
rO
2Middle alundum (Al (the Al that adds
2O
3).In order to increase the adhesiveness between protective layer 302 and the TCP window matrix 301 preferably, do not influence the corrosion resistance of protective layer simultaneously again, said Al
2O
3The weight percentage that accounts for the mixture total weight amount for smaller or equal to 10%.Preferably, Al
2O
3The weight percentage that accounts for the mixture total weight amount be 7 ~ 8%.
Fig. 4 is the schematic cross-section of the etch chamber of TCP window inner surface belt matcoveredn according to another embodiment of the present invention.
As shown in Figure 4, the top of etch chamber 400 is provided with the TCP window matrix 402 of inner surface belt matcoveredn 401, and the material of protective layer 401 adopts Y
2O
3With Al
2O
3Mixture or Z
rO
2With Al
2O
3Mixture.The thickness of said protective layer 401 is 10 ~ 20 microns; Protective layer 401 can be avoided the loss of the etching gas of etch chamber 400 inside to TCP window matrix 402; The useful life of the TCP window that has prolonged; And the thickness that guarantees the TCP window can not reduce, and the distance between plasma and the sample can not changed, and then etching technics can be produced a desired effect.In addition, because protective layer has produced good protection to the TCP window, the fragment that can avoid TCP window matrix 402 to come off because of loss makes sample produce defective, thereby has improved the stability of etching technics.
Next be described in the method that forms protective layer on the TCP window matrix.Adopt plasma spraying method in the present embodiment.The concrete operations step is described with reference to figure 5 as follows.
Fig. 5 shows and forms the schematic cross-section of the spraying equipment of protective layer according to the embodiment of the invention at TCP window inner surface.
As shown in Figure 5, the spraying range that spraying coating process can adopt LAM Research company (the technological Co., Ltd of general woods semiconductor equipment) or TEL company (Tokyo Electron Limited Tokyo Electronics Co., Ltd) to produce is 2.5 meters * 3 meters a spraying equipment 500.Spraying equipment 500 comprises spray gun 501 and dusty material injector 502.Wherein spray gun 501 comprises negative electrode 503 and anode 504, and anode 504 is connected on the nozzle of spray gun 501, and negative electrode 503 is arranged on the inside of spray gun 501.Dusty material injector 502 is arranged on the nozzle outside of spray gun 501, is added with Y in the dusty material injector 502
2O
3With Al
2O
3Mixture, said Al
2O
3The weight percentage that accounts for the mixture total weight amount be 7.5%.
At first, select the arcing gas 505 of feeding in spray gun 501, such as but not limited to nitrogen (N
2); After the energising, between negative electrode 503 and anode 504, produce electric arc 506, when arcing gas 505 passes electric arc 506, just formed plasma jet.Then, dusty material injector 502 is assigned to dusty material in the plasma jet.Will cause that the dusty material gasification forms steam because the temperature of plasma jet is too high; Said steam will cause the change of protective layer 508 compositions, and said steam causes adhesiveness variation between TCP window matrix 507 and the protective layer 508 in cohesion between TCP window matrix 507 and the protective layer 508; And the too low dusty material underheat that will make of the temperature of plasma jet; The adhesion strength of protective layer, hardness and deposition efficiency reduce; Therefore in the present embodiment the temperature of plasma jet is controlled at 12000 ~ 20000 ℃; In this temperature range, can obtain the adhesiveness between the TCP window matrix 507 and protective layer 508 preferably, and guarantee that to greatest extent the composition of protective layer 508 does not change.Plasma jet can reach 500 meter per seconds in the speed at nozzle place, dusty material fusing under the effect of this high-temperature plasma stream, and be accelerated the speed that obtains being higher than 150 meter per seconds, be ejected into and form protective layer 508 on the TCP window matrix 507.
The inner surface of TCP window of the present invention is coated with layer protective layer; Avoided the loss of etching gas to the TCP window; The thickness that guarantees the TCP window can not reduce; Thereby the distance between plasma and the sample can not changed, etching technics can be produced a desired effect, prolonged the useful life of TCP window simultaneously.In addition, because protective layer has produced good protection to the TCP window, do not drop on the surface of silicon wafer or polysilicon so do not have the forms chip that comes off yet, thereby improved the stability of etching technics.TCP window construction of the present invention is simple, is convenient to make, and therefore can be widely used in the TCP window of the etch chamber in the semiconductor manufacturing equipment.
The present invention is illustrated through the foregoing description, but should be understood that, the foregoing description just is used for for example and illustrative purposes, but not is intended to the present invention is limited in the described scope of embodiments.It will be appreciated by persons skilled in the art that in addition the present invention is not limited to the foregoing description, can also make more kinds of variants and modifications according to instruction of the present invention, these variants and modifications all drop in the present invention's scope required for protection.Protection scope of the present invention is defined by appended claims book and equivalent scope thereof.